1. Field of the Invention
This invention relates to industrial process control systems of the type including a central processor which functions in a time-share mode to make calculations respecting a large number of variables, such as process conditions, and to produce corresponding information or command signals for a variety of purposes such as positioning process valves or the like. More particularly, this invention relates to such systems having visual display means for presenting to the process operator or process engineer intelligible information to aid such personnel in exercising control over the process.
2. Description of the Prior Art
Computer-operated control systems have been in use for a number of years with various kinds of industrial processes. Such systems generally provide some form of visual data display to aid the process operating personnel, although for the most part the data displays have been relatively rudimentary and only suitable for limited purposes. Experience with such equipment has demonstrated that the process operating personnel require substantially improved facilities for communicating with the control system in order to exercise the desired close and effective control over a process. There have been a number of proposals to provide elaborate data displays with quite large display capacities, such as large-screen CRT devices. However, for various reasons such apparatus provided or proposed heretofore has not satisfactorily solved the problem.